Patent GB-190812550-A (GB)
Title: Improvement in Blowing Engines
Inventor: PETSCHE GUSTAV BERNHARD
Filed: 1908-06-11
Granted: 1909-01-07
Abstract: 12,550. Petsche, G. B. Oct. 17,1907, [date applied for under Section 91 of Patents &c. Act, 1907]. Compressing.-In a blowing-engine or air-compressor, the inlet valves are closed positively by a valve-gear which operates the valve through a yielding connexion in the form of a piston working in a vacuum cylinder ; the valves are opened by admitting air from the atmosphere to act on a second piston attached to the valve-rod ; they are held wholly or partly open during the compression strokes, by adjusting manually, or automatically in accordance with the pressure in the reservoir, a mechanically - actuated valve which controls the admission of the atmospheric air to act on the aforesaid piston. Thus, if the compressor is actuated by a gas-engine, the engine may start with the compressor unloaded. The invention is described in connexion with a blowing-engine of the kind described in Specification No. 12,784, A.D. 1903, having delivery valves and valve-gear of the kind described in Specification No. 1833, A.D. 1900. Both inlet and delivery valves are of the well-knownlgrid-iron type and are actuated through rocking-shafts D<5>, D<6> and eccentrics from a shaft D rotated tbrough enclosed gearing A<4> from the driving-shaft. Each rocking shaft D<5> is provided with a crank D<9> and connecting-rod D<1>, and operates to close the inlet valve through a yielding connexion in the form of a piston C<3> working in a vacuum cylinder C<5>, The inlet valve is opened by admitting atmospheric air by way of a passage C<6> to act on a second piston C' attached to the valverod C and working in a cylinder C'. The vacuum cylinder C<5> is formed in the trunk of the piston C<4>, A ported-cylinder oscillating valve F for controlling the admission of atmospheric air to act on the piston C' is actuated from the shaft D through an eccentric D<11>, Fig. 3, eccentric-rod D<12>, lever G, link F<3>, and arm F<2>. The adjustment of the valves F, for the purpose of holding open the inlet valves during the whole or a portion of the compression stroke, is effected by altering the position of the movable pivot G<1> of the lever G. This is effected by band, through the medium of a hand-wheel H<1>, worm H, and a toothed segment G<4> on a rocking shaft G<3> provided with arms carrying the pivot G<1>. The toothed segment is provided with an indicator G<6> showing the position of the pivot. In a modification, a ported sleeve with which the valve coacts is adjusted relatively to the valve, the eccentric-rod D<12> then being connected directly to the valve arm F<2>. To adjust the valves F automatically, a spring - pressed piston subject on its underside to the reservoir pressure is connected by a rod and links to the rocking shaft G<3>, the piston-rod also being connected to a hand-lever for adjusting the valve by band when necessary. The opening and closing movement of each inlet valve is cushioned by means of air trapped in the ends of the cylinder C', which communicate with the atmosphere through restricted passages, the restricted passage on the same side of the piston C<4> as the inlet passage C<6> being provided with a non-return valve.